from django.db import models

# Create your models here. 创建模型
# 模型就是一个类
class Topic(models.Model):
  """用户学习的主题"""
  text = models.CharField(max_length=200)
  date_added = models.DateTimeField(auto_now_add=True)

  def __str__(self):
    """返回模型的字符串表示"""
    return self.text

class Entry(models.Model):
  """学到的有关某个主题的具体知识"""
  topic = models.ForeignKey(Topic,on_delete=models.CASCADE)
  text = models.TextField()
  date_added = models.DateTimeField(auto_now_add=True)

  class Meta:
    verbose_name_plural = 'entries'
  
  def __str__(self):
    """返回模型的字符串表示"""
    if (len(self.text) > 50):
      return self.text[:50] + "..."
    else:
      return self.text
